YAP-dependent induction of UHMK1 supports nuclear enrichment of the oncogene MYBL2 and proliferation in liver cancer cells

CRKL Enhances YAP Signaling through Binding and JNK/JUN Pathway Activation in Liver Cancer

The Hippo pathway transducers yes-associated protein (YAP) and WW-domain containing transcription regulator 1 (WWTR1/TAZ) are key regulators of liver tumorigenesis, promoting tumor formation and progression. Although the first inhibitors are in clinical trials, targeting the relevant upstream regulators of YAP/TAZ activity could prove equally beneficial. To identify regulators of YAP/TAZ activity in hepatocarcinoma (HCC) cells, we carried out a proximity labelling approach (BioID) coupled with mass spectrometry. We verified CRK-like proto-oncogene adaptor protein (CRKL) as a new YAP-exclusive interaction partner. CRKL is highly expressed in HCC patients, and its expression is associated with YAP activity as well as poor survival prognosis. In vitro experiments demonstrated CRKL-dependent cell survival and the loss of YAP binding induced through actin disruption. Moreover, we delineated the activation of the JNK/JUN pathway by CRKL, which promoted YAP transcription. Our data illustrate that CRKL not only promoted YAP activity through its binding but also through the induction of YAP transcription by JNK/JUN activation. This emphasizes the potential use of targeting the JNK/JUN pathway to suppress YAP expression in HCC patients.

KIS, a target of SOX4, regulates the ID1-mediated enhancement of β-catenin to facilitate lung adenocarcinoma cell proliferation and metastasis

PURPOSE

Kinase interacting with stathmin (KIS) is a serine/threonine kinase involved in RNA processing and protein phosphorylation. Increasing evidence has suggested its involvement in cancer progression. The aim of this study was to investigate the role of KIS in the development of lung adenocarcinoma (LUAD). Dual luciferase assay was used to explore the relationship between KIS and SOX4, and its effect on ID1/β-catenin pathway.

METHODS

Real-time qPCR and western blot were used to assess the levels of KIS and other factors. Cell proliferation, migration, and invasion were monitored, and xenograft animal model were established to investigate the biological functions of KIS in vitro and in vivo.

RESULTS

In the present study, KIS was found to be highly expressed in LUAD tissues and cell lines. KIS accelerated the proliferative, migratory and invasive abilities of LUAD cells in vitro, and promoted the growth of LUAD in a mouse tumor xenograft model in vivo. Mechanistically, KIS activated the β-catenin signaling pathway by modulating the inhibitor of DNA binding 1 (ID1) and was transcriptionally regulated by SOX4 in LUAD cells.

CONCLUSION

KIS, a target of SOX4, regulates the ID1-mediated enhancement of β-catenin to facilitate LUAD cell invasion and metastasis.

Decoding the Role of O-GlcNAcylation in Hepatocellular Carcinoma

Post-translational modifications (PTMs) influence protein functionality by modulating protein stability, localization, and interactions with other molecules, thereby controlling various cellular processes. Common PTMs include phosphorylation, acetylation, ubiquitination, glycosylation, SUMOylation, methylation, sulfation, and nitrosylation. Among these modifications, O-GlcNAcylation has been shown to play a critical role in cancer development and progression, especially in hepatocellular carcinoma (HCC). This review outlines the role of O-GlcNAcylation in the development and progression of HCC. Moreover, we delve into the underlying mechanisms of O-GlcNAcylation in HCC and highlight compounds that target O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) to improve treatment outcomes. Understanding the role of O-GlcNAcylation in HCC will offer insights into potential therapeutic strategies targeting OGT and OGA, which could improve treatment for patients with HCC.

Expression and clinical significance of U2AF homology motif kinase 1 in oral squamous cell carcinoma

OBJECTIVE

U2AF homology motif kinase 1 (UHMK1) is a newly discovered molecule that may have multiple functions. Recent studies have revealed that UHMK1 had aberrant expression in many tumors and was associated with tumor progression. However, UHMK1 was rarely reported in oral squamous cell carcinoma (OSCC).

STUDY DESIGN

In this study, Western blot, quantitative real-time polymerase chain reaction (PCR), and immunohistochemistry were used to detect the expression of UHMK1 in OSCC and peritumoral non-neoplastic tissues. Then, its relationship with clinicopathologic parameters was analyzed. The Kaplan-Meier method and Cox regression model were used to analyze the effects of UHMK1 expression on the prognosis and survival of OSCC patients.

RESULTS

Our results showed that UHMK1 had higher expression in OSCC tissues compared with in peritumoral non-neoplastic tissues, and its high expression was associated with high TNM stage and lymph node metastasis. High UHMK1 expression was related to short overall and disease-free survival times. Moreover, UHMK1 expression was identified as an independent prognostic factor that influences overall and disease-free survival of OSCC patients.

CONCLUSIONS

High expression of UHMK1 is associated with the poor prognosis of patients, and it can be used as a potential prognostic molecule for OSCC.

KIS counteracts PTBP2 and regulates alternative exon usage in neurons

Alternative RNA splicing is an essential and dynamic process in neuronal differentiation and synapse maturation, and dysregulation of this process has been associated with neurodegenerative diseases. Recent studies have revealed the importance of RNA-binding proteins in the regulation of neuronal splicing programs. However, the molecular mechanisms involved in the control of these splicing regulators are still unclear. Here, we show that KIS, a kinase upregulated in the developmental brain, imposes a genome-wide alteration in exon usage during neuronal differentiation in mice. KIS contains a protein-recognition domain common to spliceosomal components and phosphorylates PTBP2, counteracting the role of this splicing factor in exon exclusion. At the molecular level, phosphorylation of unstructured domains within PTBP2 causes its dissociation from two co-regulators, Matrin3 and hnRNPM, and hinders the RNA-binding capability of the complex. Furthermore, KIS and PTBP2 display strong and opposing functional interactions in synaptic spine emergence and maturation. Taken together, our data uncover a post-translational control of splicing regulators that link transcriptional and alternative exon usage programs in neuronal development.

The oncogene MYBL2 promotes the malignant phenotype and suppresses apoptosis through hedgehog signaling pathway in clear cell renal cell carcinoma

Multiple cancers have been associated with MYB-related protein B (MYBL2), its involvement in clear cell renal cell carcinoma (ccRCC) has yet to be demonstrated. Our study revealed a significant upregulation of MYBL2 in ccRCC tissues, correlating with clinicopathological features and patient prognosis. Increased MYBL2 expression promoted cell proliferation and suppressed apoptosis. RNA-seq analysis unveiled a reduction in smoothened (SMO) expression upon MYBL2 silencing. However, luciferase and chromatin immunoprecipitation (ChIP) assays demonstrated MYBL2's positive regulation of SMO expression by directly targeting the SMO promoter. Reintroduction of SMO expression in MYBL2-knocked down cells partially restored cell proliferation and mitigated apoptosis inhibition. Overall, these results indicate that MYBL2 facilitates ccRCC progression by enhancing SMO expression, suggesting its potential as an intriguing drug target for ccRCC therapy.

From modulation of cellular plasticity to potentiation of therapeutic resistance: new and emerging roles of MYB transcription factors in human malignancies

MYB transcription factors are encoded by a large family of highly conserved genes from plants to vertebrates. There are three members of the MYB gene family in human, namely, MYB, MYBL1, and MYBL2 that encode MYB/c-MYB, MYBL1/A-MYB, and MYBL2/B-MYB, respectively. MYB was the first member to be identified as a cellular homolog of the v-myb oncogene carried by the avian myeloblastosis virus (AMV) causing leukemia in chickens. Under the normal scenario, MYB is predominantly expressed in hematopoietic tissues, colonic crypts, and neural stem cells and plays a role in maintaining the undifferentiated state of the cells. Over the years, aberrant expression of MYB genes has been reported in several malignancies and recent years have witnessed tremendous progress in understanding of their roles in processes associated with cancer development. Here, we review various MYB alterations reported in cancer along with the roles of MYB family proteins in tumor cell plasticity, therapy resistance, and other hallmarks of cancer. We also discuss studies that provide mechanistic insights into the oncogenic functions of MYB transcription factors to identify potential therapeutic vulnerabilities.

SEPTIN10-mediated crosstalk between cytoskeletal networks controls mechanotransduction and oncogenic YAP/TAZ signaling

The transcriptional co-activators of the Hippo pathway, YAP and TAZ, are regulated by mechanotransduction, which depends on dynamic actin cytoskeleton remodeling. Here, we identified SEPTIN10 as a novel cytoskeletal protein, which is transcriptionally regulated by YAP/TAZ and whose overexpression correlates with poor survival and vascular invasion in hepatocellular carcinoma (HCC) patients. Functional characterization demonstrated that SEPTIN10 promotes YAP/TAZ-dependent cell viability, migration and invasion of liver cancer cells. Mechanistically, SEPTIN10 interacts with actin and microtubule filaments supporting actin stress fiber formation and intracellular tension through binding to CAPZA2 while concurrently inhibiting microtubule polymerization through the blockage of MAP4 function. This functional antagonism is important for cytoskeleton-dependent feedback activation of YAP/TAZ, as microtubule depolymerization induces actin stress fiber formation and subsequently YAP/TAZ activity. Importantly, the crosstalk between microfilaments and microtubules is mediated by SEPTIN10 as its loss abrogates actin stress fiber formation after microtubule disruption. Together, the YAP/TAZ target gene SEPTIN10 controls the dynamic interplay between actin and microtubule filaments, which feeds back on Hippo pathway activity in HCC cells and thus acts as molecular switch with impact on oncogenic signaling and cancer cell biology.

Exploration of a hypoxia-immune-related microenvironment gene signature and prediction model for hepatitis C-induced early-stage fibrosis

BACKGROUND

Liver fibrosis contributes to significant morbidity and mortality in Western nations, primarily attributed to chronic hepatitis C virus (HCV) infection. Hypoxia and immune status have been reported to be significantly correlated with the progression of liver fibrosis. The current research aimed to investigate the gene signature related to the hypoxia-immune-related microenvironment and identify potential targets for liver fibrosis.

METHOD

Sequencing data obtained from GEO were employed to assess the hypoxia and immune status of the discovery set utilizing UMAP and ESTIMATE methods. The prognostic genes were screened utilizing the LASSO model. The infiltration level of 22 types of immune cells was quantified utilizing CIBERSORT, and a prognosis-predictive model was established based on the selected genes. The model was also verified using qRT-PCR with surgical resection samples and liver failure samples RNA-sequencing data.

RESULTS

Elevated hypoxia and immune status were linked to an unfavorable prognosis in HCV-induced early-stage liver fibrosis. Increased plasma and resting NK cell infiltration were identified as a risk factor for liver fibrosis progression. Additionally, CYP1A2, CBS, GSTZ1, FOXA1, WDR72 and UHMK1 were determined as hypoxia-immune-related protective genes. The combined model effectively predicted patient prognosis. Furthermore, the preliminary validation of clinical samples supported most of the conclusions drawn from this study.

CONCLUSION

The prognosis-predictive model developed using six hypoxia-immune-related genes effectively predicts the prognosis and progression of liver fibrosis. The current study opens new avenues for the future prediction and treatment of liver fibrosis.

α-catenin interaction with YAP/FoxM1/TEAD-induced CEP55 supports liver cancer cell migration

BACKGROUND

Adherens junctions (AJs) facilitate cell-cell contact and contribute to cellular communication as well as signaling under physiological and pathological conditions. Aberrant expression of AJ proteins is frequently observed in human cancers; however, how these factors contribute to tumorigenesis is poorly understood. In addition, for some factors such as α-catenin contradicting data has been described. In this study we aim to decipher how the AJ constituent α-catenin contributes to liver cancer formation.

METHODS

TCGA data was used to detect transcript changes in 23 human tumor types. For the detection of proteins, liver cancer tissue microarrays were analyzed by immunohistochemistry. Liver cancer cell lines (HLF, Hep3B, HepG2) were used for viability, proliferation, and migration analyses after RNAinterference-mediated gene silencing. To investigate the tumor initiating potential, vectors coding for α-catenin and myristoylated AKT were injected in mice by hydrodynamic gene delivery. A BioID assay combined with mass spectrometry was performed to identify α-catenin binding partners. Results were confirmed by proximity ligation and co-immunoprecipitation assays. Binding of transcriptional regulators at gene promoters was investigated using chromatin-immunoprecipitation.

RESULTS

α-catenin mRNA was significantly reduced in many human malignancies (e.g., colon adenocarcinoma). In contrast, elevated α-catenin expression in other cancer entities was associated with poor clinical outcome (e.g., for hepatocellular carcinoma; HCC). In HCC cells, α-catenin was detectable at the membrane as well as cytoplasm where it supported tumor cell proliferation and migration. In vivo, α-catenin facilitated moderate oncogenic properties in conjunction with AKT overexpression. Cytokinesis regulator centrosomal protein 55 (CEP55) was identified as a novel α-catenin-binding protein in the cytoplasm of HCC cells. The physical interaction between α-catenin and CEP55 was associated with CEP55 stabilization. CEP55 was highly expressed in human HCC tissues and its overexpression correlated with poor overall survival and cancer recurrence. Next to the α-catenin-dependent protein stabilization, CEP55 was transcriptionally induced by a complex consisting of TEA domain transcription factors (TEADs), forkhead box M1 (FoxM1), and yes-associated protein (YAP). Surprisingly, CEP55 did not affect HCC cell proliferation but significantly supported migration in conjunction with α-catenin.

CONCLUSION

Migration-supporting CEP55 is induced by two independent mechanisms in HCC cells: stabilization through interaction with the AJ protein α-catenin and transcriptional activation via the FoxM1/TEAD/YAP complex.

UHMK1 promotes lung adenocarcinoma oncogenesis by regulating the PI3K/AKT/mTOR signaling pathway

BACKGROUND

Effective targeted therapy for lung adenocarcinoma (LUAD), the number one cancer killer worldwide, continues to be a difficult problem because of the limitation of number of applicable patients and acquired resistance. Identifying more promising drug targets for LUAD treatment holds immense clinical significance. Recent studies have revealed that the U2 auxiliary factor (U2AF) homology motif kinase 1 (UHMK1) is a robust pro-oncogenic factor in many cancers. However, its biological functions and the underlying molecular mechanisms in LUAD have not been investigated.

METHODS

The UHMK1 expression in LUAD cells and tissues was evaluated by bioinformatics analysis, immunohistochemistry (IHC), western blotting (WB), and real time quantitative polymerase chain reaction (RT-qPCR) assays. A series of gain- and loss-of-function experiments for UHMK1 were carried out to investigate its biological functions in LUAD in vitro and in vivo. The mechanisms underlying UHMK1's effects in LUAD were analyzed by transcriptome sequencing and WB assays.

RESULTS

UHMK1 expression was aberrantly elevated in LUAD tumors and cell lines and positively correlated with tumor size and unfavorable patient prognosis. Functionally, UHMK1 displayed robust pro-oncogenic capacity in LUAD and mechanistically exerted its biological effects via the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway.

CONCLUSION

UHMK1 is a potent oncogene in LUAD. Targeting UHMK1 may significantly improve the effect of LUAD treatment via inhibiting multiple biological ways of LUAD progression.

UHMK1 is a novel splicing regulatory kinase

The U2AF Homology Motif Kinase 1 (UHMK1) is the only kinase that contains the U2AF homology motif, a common protein interaction domain among splicing factors. Through this motif, UHMK1 interacts with the splicing factors SF1 and SF3B1, known to participate in the 3' splice site recognition during the early steps of spliceosome assembly. Although UHMK1 phosphorylates these splicing factors in vitro, the involvement of UHMK1 in RNA processing has not previously been demonstrated. Here, we identify novel putative substrates of this kinase and evaluate UHMK1 contribution to overall gene expression and splicing, by integrating global phosphoproteomics, RNA-seq, and bioinformatics approaches. Upon UHMK1 modulation, 163 unique phosphosites were differentially phosphorylated in 117 proteins, of which 106 are novel potential substrates of this kinase. Gene Ontology analysis showed enrichment of terms previously associated with UHMK1 function, such as mRNA splicing, cell cycle, cell division, and microtubule organization. The majority of the annotated RNA-related proteins are components of the spliceosome but are also involved in several steps of gene expression. Comprehensive analysis of splicing showed that UHMK1 affected over 270 alternative splicing events. Moreover, splicing reporter assay further supported UHMK1 function on splicing. Overall, RNA-seq data demonstrated that UHMK1 knockdown had a minor impact on transcript expression and pointed to UHMK1 function in epithelial-mesenchymal transition. Functional assays demonstrated that UHMK1 modulation affects proliferation, colony formation, and migration. Taken together, our data implicate UHMK1 as a splicing regulatory kinase, connecting protein regulation through phosphorylation and gene expression in key cellular processes.

Transcription factor E2F8 is a therapeutic target in the basal-like subtype of breast cancer

Introduction

Tumorigenesis in breast cancers usually accompanied by the dysregulation of transcription factors (TFs). Abnormal amplification of TFs leads aberrant expression of its downstream target genes. However, breast cancers are heterogeneous disease with different subtypes that have distinguished clinical behaviours, and the identification of prognostic TFs may enable to provide diagnosis and treatment of breast cancer based on subtypes, especially in Basal-like breast cancer.

Methods

The RNA-sequencing was performed to screen differential TFs in breast cancer subtypes. The GEPIA dataset analysis was used to analyze the genes expression in invasive breast carcinoma. The expression of MYBL2, HOXC13, and E2F8 was verified by qRT-PCR assay in breast cancers. The depiction analysis of co-expressed proteins was revealed using the STRING datasets. The cellular infiltration level analysis by the TISIDB and TIMER databases. The transwell assay was performed to analyze cellular migration and invasion. CCK-8 assay was used to evaluate cellular drug susceptibility for docetaxel treatment. Predicted targeted drugs in breast cancers by GSCA Lite database online.

Results

Kaplan-Meier plotter suggested that high expression of both E2F8 and MYBL2 in Basal-like subtype had a poor relapse-free survival. Functional enrichment results identified that apoptosis, cell cycle, and hormone ER pathway were represented the crucial regulation pathways by both E2F8 and MYBL2. In the meantime, database analysis indicated that high expression of E2F8 responded to chemotherapy, while those patients of high expression of MYBL2 responded to endocrinotherapy, and a positive correlation between the expression of E2F8 and PD-L1/CTLA4. Our cell line experiments confirmed the importance of E2F8 and MYBL2 in proliferation and chemotherapy sensitivity, possibly, the relationship with PD-L1. Additionally, we also observed that the up-regulation of E2F8 was accompanied with higher enrichments of CD4+ T cells and CD8+ T cells in breast cancers.

Conclusion

Taken together, our findings elucidated a prospective target in Basal-like breast cancer, providing underlying molecular biomarkers for the development of breast cancer treatment.

A Novel Artificial Neural Network Prognostic Model Based on a Cancer-Associated Fibroblast Activation Score System in Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) ranks fourth as the most common cause of cancer-related death. It is vital to identify the mechanism of progression and predict the prognosis for patients with HCC. Previous studies have found that cancer-associated fibroblasts (CAFs) promote tumor proliferation and immune exclusion. However, the information about CAF-related genes is still elusive.

Methods

The data were obtained from The Cancer Genome Atlas, International Cancer Genome Consortium, and Gene Expression Omnibus databases. On the basis of single-cell transcriptome and ligand–receptor interaction analysis, CAF-related genes were selected. By performing Cox regression and random forest, we filtered 12 CAF-related prognostic genes for the construction of the ANN model based on the CAF activation score (CAS). Then, functional, immune, mutational, and clinical analyses were performed.

Results

We constructed a novel ANN prognostic model based on 12 CAF-related prognostic genes. Cancer-related pathways were enriched, and higher activated cell crosstalk was identified in high-CAS samples. High immune activity was observed in high-CAS samples. We detected three differentially mutated genes (NBEA, RYR2, and FRAS1) between high- and low-CAS samples. In clinical analyses, we constructed a nomogram to predict the prognosis of patients with HCC. 5-Fluorouracil had higher sensitivity in high-CAS samples than in low-CAS samples. Moreover, some small-molecule drugs and the immune response were predicted.

Conclusion

We constructed a novel ANN model based on CAF-related genes. We revealed information about the ANN model through functional, mutational, immune, and clinical analyses.

E2F2 promotes lung adenocarcinoma progression through B-Myb- and FOXM1-facilitated core transcription regulatory circuitry

Lung adenocarcinoma (LUAD) causes severe cancer death worldwide. E2F2 is a canonical transcription factor implicated in transcription regulation, cell cycle and tumorigenesis. The role of E2F2 as well as its transcription regulatory network in LUAD remains obscure. In this study, we constructed a weighted gene co-expression network and identified several key modules and networks overrepresented in LUAD, including the E2F2-centered transcription regulatory network. Function analysis revealed that E2F2 overexpression accelerated cell growth, cell cycle progression and cell motility in LUAD cells whereas E2F2 knockdown inhibited these malignant phenotypes. Mechanistic investigations uncovered various E2F2-regulated downstream genes and oncogenic signaling pathways. Notably, three core transcription factors of E2F2, B-Myb and FOXM1 from the LUAD transcription regulatory network exhibited positive expression correlation, associated with each other, mutually transactivated each other, and regulated similar downstream gene cascades, hence constituting a consolidated core transcription regulatory circuitry. Moreover, E2F2 could promote and was essentially required for LUAD growth in orthotopic mouse models. Prognosis modeling revealed that a two-gene signature of E2F2 and PLK1 from the transcription regulatory circuitry remarkably stratified patients into low- and high-risk groups. Collectively, our results clarified the critical roles of E2F2 and the exquisite core transcription regulatory circuitry of E2F2/B-Myb/FOXM1 in LUAD progression.

Downstream Regulatory Network of MYBL2 Mediating Its Oncogenic Role in Melanoma

The transcription factor MYBL2 is widely expressed in proliferating cells. Aberrant expression of MYBL2 contributes to tumor malignancy and is associated with poor patient prognosis. However, the downstream transcriptional network that mediates its oncogenic properties remains elusive. In the present study, we observed that MYBL2 was overexpressed in malignant and metastatic melanoma patient samples and that the high expression level of MYBL2 was significantly associated with poor prognosis. A loss-of-function study demonstrated that MYBL2 depletion significantly decreased cell proliferation and migration and prevented cell cycle progression. We also determined that MYBL2 promoted the formation of melanoma stem-like cell populations, indicating its potential as a therapeutic target for treating resistant melanoma. Mechanistically, we constructed an MYBL2 regulatory network in melanoma by integrating RNA-seq and ChIP-seq data. EPPK1, PDE3A, and FCGR2A were identified as three core target genes of MYBL2. Importantly, multivariate Cox regression and survival curve analysis revealed that PDE3A and EPPK1 were negatively correlated with melanoma patient survival; however, FCGR2A was positively correlated with patient survival. Overall, our findings elucidate an MYBL2 regulatory network related to cell proliferation and cancer development in melanoma, suggesting that MYBL2 may be potentially targeted for melanoma diagnosis and treatment.

UHMK1 aids colorectal cancer cell proliferation and chemoresistance through augmenting IL-6/STAT3 signaling

UHMK1, a serine/threonine kinase with a U2AF homology motif, is implicated in RNA processing and protein phosphorylation. Increasing evidence has indicated its involvement in tumorigenesis. However, it remains to be elucidated whether UHMK1 plays a role in the development of colorectal cancer (CRC). Here, we demonstrated that UHMK1 was frequently upregulated in CRC samples compared with adjacent normal tissue and high expression of UHMK1 predicted poor outcomes. Knockdown of UHMK1 by siRNAs restrained CRC cell proliferation and increased oxaliplatin sensitivity, whereas overexpression of UHMK1 promoted CRC cell growth and oxaliplatin resistance, suggesting that UHMK1 plays important oncogenic roles in CRC. Mechanistically, we showed that UHMK1 had a significant effect on IL6/STAT3 signaling by interacting with STAT3. The interaction of UHMK1 with STAT3 enhanced STAT3 activity in regulating gene transcription. Furthermore, we found that STAT3 could in turn transcriptionally activate UHMK1 expression in CRC cells. The complementary experiments for cell growth and oxaliplatin resistance indicated the interdependent relationship between UHMK1 and STAT3. Thus, these collective findings uncovered a new UHMK1/STAT3 positive feedback regulatory loop contributing to CRC development and chemoresistance.

Structure and function of MuvB complexes

Proper progression through the cell-division cycle is critical to normal development and homeostasis and is necessarily misregulated in cancer. The key to cell-cycle regulation is the control of two waves of transcription that occur at the onset of DNA replication (S phase) and mitosis (M phase). MuvB complexes play a central role in the regulation of these genes. When cells are not actively dividing, the MuvB complex DREAM represses G1/S and G2/M genes. Remarkably, MuvB also forms activator complexes together with the oncogenic transcription factors B-MYB and FOXM1 that are required for the expression of the mitotic genes in G2/M. Despite this essential role in the control of cell division and the relationship to cancer, it has been unclear how MuvB complexes inhibit and stimulate gene expression. Here we review recent discoveries of MuvB structure and molecular interactions, including with nucleosomes and other chromatin-binding proteins, which have led to the first mechanistic models for the biochemical function of MuvB complexes.

Acquired Resistance to Antiangiogenic Therapies in Hepatocellular Carcinoma Is Mediated by Yes-Associated Protein 1 Activation and Transient Expansion of Stem-Like Cancer Cells

Induction of neoangiogenesis is a hallmark feature during disease progression of hepatocellular carcinoma (HCC). Antiangiogenetic compounds represent a mainstay of therapeutic approaches; however, development of chemoresistance is observed in the majority of patients. Recent findings suggest that tumor-initiating cells (TICs) may play a key role in acquisition of resistance, but the exact relevance for HCC in this process remains to be defined. Primary and established hepatoma cell lines were exposed to long-term sorafenib treatment to model acquisition of resistance. Treatment effects on TICs were estimated by sphere-forming capacity in vitro, tumorigenicity in vivo, and flow cytometry. Adaptive molecular changes were assessed by whole transcriptome analyses. Compensatory mechanisms of resistance were identified and directly evaluated. Sustained antiproliferative effect following sorafenib treatment was observed in three of six HCC cell lines and was followed by rapid regrowth, thereby mimicking responses observed in patients. Resistant cells showed induction in sphere forming in vitro and tumor-initiating capacity in vivo as well as increased number of side population and epithelial cell adhesion molecule-positive cells. Conversely, sensitive cell lines showed consistent reduction of TIC properties. Gene sets associated with resistance and poor prognosis, including Hippo/yes-associated protein (YAP), were identified. Western blot and immunohistochemistry confirmed increased levels of YAP. Combined treatment of sorafenib and specific YAP inhibitor consistently revealed synergistic antioncogenic effects in resistant cell lines. Conclusion: Resistance to antiangiogenic therapy might be driven by transient expansion of TICs and activation of compensatory pro-oncogenic signaling pathways, including YAP. Specific targeting of TICs might be an effective therapeutic strategy to overcome resistance in HCC.

ETV4 potentiates nuclear YAP retention and activities to enhance the progression of hepatocellular carcinoma

Dysregulation of the Hippo pathway that promotes cell survival, proliferation and tumorigenesis, relays on the coordinated interactions of YAP with the factors that determine YAP translocation and the related transcriptional programming. Here, we demonstrate that ETV4, a transcriptional factor participating in various protumorigenic processes, enhances YAP-mediated transactivation and hepatocellular carcinoma (HCC) progression. Mechanistically, the enhancement of YAP activities is mediated by the interaction between ETV4 and YAP, which not only increases nuclear YAP accumulation but also directly augments the YAP/TEAD4-mediated transcriptional activation in tumor cells. Functionally, the interplay of ETV4 and YAP promotes growth of liver tumor cells, and activates the genes related to myeloid cell recruitment, including CXCL1 and CXCL5, leading to an enriched presence of myeloid-derived suppressive cells and macrophages but a decreased infiltration of T cells and NK cells in transplanted tumors. More importantly, the correlations between YAP activation, the altered immune cell distribution and ETV4 expression are observed in human HCCs. Therefore, our study reveals a functional interaction between ETV4 and YAP that contributes to HCC progression, and provides mechanistic insights into the regulation of nuclear YAP retention and transactivation.

UHMK1 Is a Novel Marker for Personalized Prediction of Pancreatic Cancer Prognosis

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer mortality, and new therapeutic options are urgently needed. Long noncoding RNA H19 (H19) is known to promote PDAC progression, but the downstream genes of H19 are largely unknown. Five PDAC cell lines, nonmalignant pancreatic cells, TCGA, GEO-derived pancreatic tissues (malignant, n=413; nonmalignant, n=234), a pancreatic tissue array (n=96), and pancreatic tissues from our clinic (malignant, n=20; nonmalignant, n=20) were examined by a gene array, RT-qPCR, Western blotting, MTT, colony formation, wound-healing, siRNA-mediated gene silencing, bioinformatics, xenotransplantation, and immunohistochemistry assays. The cell cycle inhibitor, UHMK1, was identified to have the strongest correlation with H19. UHMK1 expression was enhanced in PDAC, and high UHMK1 expression correlated with tumor stage, and lower overall survival. siRNA-mediated UHMK1 downregulation inhibited progression signaling. siRNA-mediated downregulation of H19 or UHMK1 inhibited tumor proliferation and xenograft growth. Based on the correlation between UHMK1 expression and clinical parameters, we developed a nomogram that reliably predicts patient prognosis and overall survival. Together, we characterized UHMK1 as an H19-induced oncogene and verified it as a novel PDAC prognostic marker for overall survival.

MYB proto-oncogene like 2 promotes hepatocellular carcinoma growth and glycolysis via binding to the Optic atrophy 3 promoter and activating its expression

Optic atrophy 3 (OPA3) is an integral protein of the mitochondrial outer membrane. The current study explored the expression of OPA3 in hepatocellular carcinoma (HCC), its association with the prognosis and its involvement in HCC cell proliferation and aerobic glycolysis. In addition, the transcription factors that activate its expression were screened and validated. Gene expression data in normal liver and liver cancer were acquired from the Genotype-Tissue Expression Project (GTEx) and The Cancer Genome Atlas (TCGA)-Liver Hepatocellular Carcinoma (TCGA-LIHC). Chromatin immunoprecipitation-seq data (GSM1010876) in Cistrome Data Browser was used for searching transcriptional factors binding to the OPA3 promoter. HCC cell lines HLF and JHH2 were used for in-vitro and in-vivo studies. Results showed that OPA3 is significantly upregulated in HCC and associated with unfavorable prognosis. OPA3 knockdown impaired HCC cell growth in vitro and in vivo. Besides, it decreased glucose uptake, lactate production, intracellular ATP levels, and extracellular acidification rate (ECAR) of HLF and JHH2 cells. MYB Proto-Oncogene Like 2 (MYBL2) can bind to the promoter of OPA3 and enhance its transcription. MYBL2 knockdown decreased aerobic glycolysis in HCC cells. OPA3 overexpression reversed these alterations. In conclusion, this study revealed a novel MYBL2-OPA3 axis that enhances HCC cell proliferation and aerobic glycolysis.

FOXM1-induced TYMS upregulation promotes the progression of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and one of the major causes of cancer-related death. Thymidylate synthase (TYMS) catalyzes the methylation of deoxy guanosine to deoxy thymidylate, which is a crucial gene for DNA repair and replication. Thus, TYMS was reported to be closely associated with developing a variety of tumors, but it has been poorly studied in HCC.

Materials and methods

We used the cell counting kit-8 (CCK-8), BrdU, and CFSE assay to measure cell proliferation. The flow cytometry assay and the TUNEL assay were used for assessing cell apoptosis. The flow cytometry assay was used to analyze the cell cycle. The Transwell invasion assay and the wound healing assay were conducted to determine the invasive ability of the cells. RT-qPCR and Western blot analyses were performed to evaluate the mRNA and protein expression levels of specific genes, respectively.

Results

TYMS was found to be upregulated in both HCC cells and patient samples. High expression of TYMS was associated with an unfavorable prognosis in HCC patients based on the TCGA-LIHC dataset. Cell proliferation, apoptosis, and invasion assays revealed that TYMS promoted the proliferation and invasion of HCC cells as well as inhibited apoptosis. In addition, TYMS is a downstream target of FOXM1. TYMS knockdown reversed the 5-FU resistance caused by FOXM1 overexpression and re-sensitized HCC cells to 5-FU treatment.

Conclusion

This study suggested that TYMS serves as an oncogene in HCC, and targeting the FOXM1-TYMS axis may help improve the survival of HCC patients as well as provide new insights for treating advanced HCC patients.

Cyclin-dependent kinase 1 as a potential target for lycorine against hepatocellular carcinoma

The pathological changes and possible underlying molecular mechanisms of hepatocellular carcinoma (HCC) are currently unclear. Effective treatment of this pathological state remains a challenge. The purpose of this study is to obtain some key genes with diagnostic and prognostic meaning and to identify potential therapeutic agents for HCC treatment. Here, CDK1, CCNB1 and CCNB2 were found to be highly expressed in HCC patients and accompanied by poor prognosis, and knockdown of them by siRNA drastically induced autophagy and senescence in hepatoma cells. Simultaneously, the anti-HCC effect of lycorine was comparable to that of interfering with these three genes, and lycorine significantly promoted the decrease both in protein and mRNA expression of CDK1. Molecular validation mechanistically demonstrated that lycorine might attenuate the degradation rate of CDK1 via interaction with it, which had been confirmed by cellular thermal shift assay and drug affinity responsive targets stability assay. Taken together, these findings suggested that CDK1, CCNB1 and CCNB2 could be regarded as potential diagnostic and prognostic biomarkers for HCC, and CDK1 might serve as a promising therapeutic target for lycorine against HCC.

Co-expression of YAP and TAZ associates with chromosomal instability in human cholangiocarcinoma

Background

Activation of the oncogene yes-associated protein (YAP) is frequently detected in intrahepatic cholangiocarcinoma (iCCA); however, the expression pattern and the functional impact of its paralogue WW domain-containing transcription regulator 1 (WWTR1; synonym: TAZ) are not well described in different CCA subtypes.

Methods

Immunohistochemical analysis of YAP and TAZ in iCCA and extrahepatic CCA (eCCA) cohorts was performed. YAP/TAZ shuttling and their functional impact on CCA cell lines were investigated. Target genes expression after combined YAP/TAZ inhibition was analyzed.

Results

Immunohistochemical analysis of iCCA and eCCA revealed YAP or TAZ positivity in up to 49.2%; however, oncogene co-expression was less frequent (up to 23%). In contrast, both proteins were jointly detectable in most CCA cell lines and showed nuclear/cytoplasmic shuttling in a cell density-dependent manner. Next to the pro-proliferative function of YAP/TAZ, both transcriptional co-activators cooperated in the regulation of a gene signature that indicated the presence of chromosomal instability (CIN). A correlation between YAP and the CIN marker phospho-H2A histone family member X (pH2AX) was particularly observed in tissues from iCCA and distal CCA (dCCA). The presence of the CIN genes in about 25% of iCCA was statistically associated with worse prognosis.

Conclusions

YAP and TAZ activation is not uncoupled from cell density in CCA cells and both factors cooperatively contribute to proliferation and expression of CIN-associated genes. The corresponding group of CCA patients is characterized by CIN and may benefit from YAP/TAZ-directed therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08794-5.

Pan-cancer analysis indicates that MYBL2 is associated with the prognosis and immunotherapy of multiple cancers as an oncogene

MYBL2 has been demonstrated to be an oncogene in some cancers, but there is no pan-cancer analysis at the macro level. We used multiple online or offline bioinformatic tools to examine the effects of MYBL2 in human cancers. We first identified that MYBL2 was highly expressed and related to the stage and grade of most cancers. The results of survival analysis from two databases showed that high MYBL2 expression was positively correlated with a poor prognosis for most cancer patients. We observed a significant difference in the promoter methylation level of MYBL2 in cancers such as colon adenocarcinoma and liver hepatocellular carcinoma versus normal controls. We found that MYBL2 can affect the tumor immune microenvironment by influencing the immune infiltration level and expression level of CD4⁺ T cells, CD8⁺ T cells, cancer-associated fibroblasts (CAFs) and immune checkpoint-associated cells. Functional enrichment analysis of MYBL2 identified that MYBL2 can play a crucial role in cancers by regulating spliceosomes, DNA replication and the cell cycle. Moreover, we verified the function of MYBL2 in three cancer cells of glioma, breast cancers and liver cancers, and the results showed that MYBL2 can regulate the cell cycle and proliferation ability of cancers.

MYBL2 Gene Polymorphism Is Associated With Acute Lymphoblastic Leukemia Susceptibility in Children

Purpose

Although MYBL2 had been validated to participate in multiple cancers including leukemia, the role of MYBL2 polymorphisms in acute lymphoblastic leukemia (ALL) was still not clear. In this study, we aimed to evaluate the association between MYBL2 single nucleotide polymorphisms (SNPs) and ALL risk in children.

Methods

A total of 687 pediatric ALL cases and 971 cancer-free controls from two hospitals in South China were recruited. A case-control study by genotyping three SNPs in the MYBL2 gene (rs285162 C>T, rs285207 A>C, and rs2070235 A>G) was conducted. The associations were assessed by odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Subgroup and stratification analyses were conducted to explore the association of rs285207 with ALL risk in terms of age, sex, immunophenotype, risk level, and other clinical characteristics. The false-positive report probability (FPRP) analysis was performed to verify each significant finding. Functional analysis in silico was used to evaluate the probability that rs285207 might influence the regulation of MYBL2 .

Results

Our study demonstrated that rs285207 was related to a decreased ALL risk (adjusted OR = 0.78; 95% CI = 0.63-0.97, P = 0.022) in the dominant model. The associations of rs285207 with ALL risk appeared stronger in patients with pre B ALL (adjusted OR=0.56; 95% CI=0.38-0.84, P=0.004), with normal diploid (adjusted OR=0.73; 95% CI=0.57-0.95, P=0.017), with low risk (adjusted OR=0.68; 95% CI=0.49-0.94, P=0.021), with lower WBC (adjusted OR=0.62; 95% CI=0.43-0.87, P=0.007) or lower platelet level (adjusted OR=0.76; 95% CI=0.59-0.96, P=0.023). With FPRP analysis, the significant association between the rs285207 polymorphism and decreased ALL risk was still noteworthy (FPRP=0.128). Functional analysis showed that IKZF1 bound to DNA motif overlapping rs285207 and had a higher preference for the risk allele A. As for rs285162 C>T and rs2070235 A>G, no significant was found between them and ALL risk.

Conclusion

In this study, we revealed that rs285207 polymorphism decreased the ALL risk in children, and rs285207 might alter the binding to IKZF1, which indicated that the MYBL2 gene polymorphism might be a potential biomarker of childhood ALL.

Oncogenic PAX6 elicits CDK4/6 inhibitor resistance by epigenetically inactivating the LATS2-Hippo signaling pathway

Intrinsic resistance to CDK4/6 inhibitors hinders their clinical utility in cancer treatment. Furthermore, the predictive markers of CDK4/6 inhibitors in gastric cancer (GC) remain incompletely described. Here, we found that PAX6 expression was negatively correlated with the response to palbociclib in vitro and in vivo in GC. We observed that the PAX6 expression level was negatively correlated with the overall survival of GC patients and further showed that PAX6 can promote GC cell proliferation and the cell cycle. The cell cycle is regulated by the interaction of cyclins with their partner serine/threonine cyclin-dependent kinases (CDKs), and the G1/S-phase transition is the main target of CDK4/6 inhibitors. Therefore, we tested whether PAX6 expression was correlated with the GC response to palbociclib. We found that PAX6 hypermethylates the promoter of LATS2 and inactivates the Hippo pathway, which upregulates cyclin D1 (CCND1) expression. This results in a suppressed response to palbociclib in GC. Furthermore, we found that the induction of the Hippo signaling pathway or treatment with a DNA methylation inhibitor could overcome PAX6-induced palbociclib resistance in GC. These findings uncover a tumor promoter function of PAX6 in GC and establish overexpressed PAX6 as a mechanism of resistance to palbociclib.

hsa-miR-374b-5p regulates expression of the gene U2AF homology motif (UHM) kinase 1

OBJECTIVE

We aimed to identify a microRNA (miRNA) that is significantly upregulated in blood and in cells of the oral mucosa upon exposure to the periodontitis main risk factors oral inflammation and tobacco smoke, to subsequently identify its target gene and to describe the molecular mechanism of gene regulation.

BACKGROUND

miRNAs are associated with many disorders. Array-based miRNA expression studies indicated a number of differentially expressed miRNAs in the pathology of oral diseases. However, these miRNAs mostly lacked replication, and their target genes have remained unknown.

METHODS

863 miRNAs were analyzed in blood from 18 PD cases and 70 controls (Geniom Biochip). Selected miRNAs were analyzed for upregulation in the inflamed oral mucosa of PD patients using published miRNA expression profiling studies from gingival cells. hsa-miR-374b-5p mimic was overexpressed in primary gingival fibroblasts (pGFs) from 3 donors, and genome-wide mRNA expression was quantified (Clarion Array). Gene-specific regulation was validated by qRT-PCR and Luciferase activity in HeLa cells.

RESULTS

hsa-miR-374b-5p showed >twofold change (FC) in 3 independent studies performed in blood, gingival tissues, and cells. After hsa-miR-374b-5p overexpression, genome-wide expression analysis showed UHMK1 as top 1 downregulated gene in pGFs (p = 2.5 × 10^-04 , fold change = -1.8). Reporter genes demonstrated that hsa-miR-374b-5p downregulates mRNA levels (p = .02; FC = -1.5), leading to reduction in protein activity (p = .013, FC = -1.3).

CONCLUSIONS

hsa-miR-374b-5p is upregulated in blood and ginvial cells exposed to oral inflammation and tobacco smoke and regulates UHMK1, which has a role in osteoclast differentiation.

Extracellular vesicles derived from ascitic fluid enhance growth and migration of ovarian cancer cells

Ovarian cancer is associated with a high mortality rate due to diagnosis at advanced stages. Dissemination often occurs intraperitoneally within the ascites fluid. The microenvironment can support dissemination through several mechanisms. One potential ascites factor which may mediate dissemination are EVs or extracellular vesicles that can carry information in the form of miRNAs, proteins, lipids, and act as mediators of cellular communication. We present our observations on EVs isolated from ascitic supernatants from patients diagnosed with high grade serous ovarian carcinoma in augmenting motility, growth, and migration towards omental fat. MicroRNA profiling of EVs from malignant ascitic supernatant demonstrates high expression of miR 200c-3p, miR18a-5p, miR1246, and miR1290 and low expression of miR 100- 5p as compared to EVs isolated from benign ascitic supernatant. The migration of ovarian cancer spheroids towards omental fat is enhanced in the presence of malignant ascitic EVs. Gene expression of these cells showed increased expression of ZBED2, ZBTB20, ABCC3, UHMK1, and low expression of Transgelin and MARCKS. We present evidence that ovarian ascitic EVs increase the growth of ovarian cancer spheroids through miRNAs.

MYBL2 disrupts the Hippo-YAP pathway and confers castration resistance and metastatic potential in prostate cancer

Rationale: Resistance to androgen-deprivation therapy (ADT) associated with metastatic progression remains a challenging clinical task in prostate cancer (PCa) treatment. Current targeted therapies for castration-resistant prostate cancer (CRPC) are not durable. The exact molecular mechanisms mediating resistance to castration therapy that lead to CRPC progression remain obscure. Methods: The expression of MYB proto-oncogene like 2 (MYBL2) was evaluated in PCa samples. The effect of MYBL2 on the response to ADT was determined by in vitro and in vivo experiments. The survival of patients with PCa was analyzed using clinical specimens (n = 132) and data from The Cancer Genome Atlas (n = 450). The mechanistic model of MYBL2 in regulating gene expression was further detected by subcellular fractionation, western blotting, quantitative real-time PCR, chromatin immunoprecipitation, and luciferase reporter assays. Results: MYBL2 expression was significantly upregulated in CRPC tissues and cell lines. Overexpression of MYBL2 could facilitate castration-resistant growth and metastatic capacity in androgen-dependent PCa cells by promoting YAP1 transcriptional activity via modulating the activity of the Rho GTPases RhoA and LATS1 kinase. Importantly, targeting MYBL2, or treatment with either the YAP/TAZ inhibitor Verteporfin or the RhoA inhibitor Simvastatin, reversed the resistance to ADT and blocked bone metastasis in CRPC cells. Finally, high MYBL2 levels were positively associated with TNM stage, total PSA level, and Gleason score and predicted a higher risk of metastatic relapse and poor prognosis in patients with PCa. Conclusions: Our results reveal a novel molecular mechanism conferring resistance to ADT and provide a strong rationale for potential therapeutic strategies against CRPC.

MYB oncoproteins: emerging players and potential therapeutic targets in human cancer

MYB transcription factors are highly conserved from plants to vertebrates, indicating that their functions embrace fundamental mechanisms in the biology of cells and organisms. In humans, the MYB gene family is composed of three members: MYB, MYBL1 and MYBL2, encoding the transcription factors MYB, MYBL1, and MYBL2 (also known as c-MYB, A-MYB, and B-MYB), respectively. A truncated version of MYB, the prototype member of the MYB family, was originally identified as the product of the retroviral oncogene v-myb, which causes leukaemia in birds. This led to the hypothesis that aberrant activation of vertebrate MYB could also cause cancer. Despite more than three decades have elapsed since the isolation of v-myb, only recently investigators were able to detect MYB genes rearrangements and mutations, smoking gun evidence of the involvement of MYB family members in human cancer. In this review, we will highlight studies linking the activity of MYB family members to human malignancies and experimental therapeutic interventions tailored for MYB-expressing cancers.

Identification and validation of a hub gene prognostic index for hepatocellular carcinoma

Aims: We aim to provide new insights into the mechanisms of hepatocellular carcinoma (HCC) and identify key genes as biomarkers for the prognosis of HCC. Materials & methods: Differentially expressed genes between HCC tissues and normal tissues were identified via the Gene Expression Omnibus tool. The top ten hub genes screened by the degree of the protein nodes in the protein-protein interaction network also showed significant associations with overall survival in HCC patients. Results: A prognostic model containing a five-gene signature was constructed to predict the prognosis of HCC via multivariate Cox regression analysis. Conclusion: This study identified a novel five-gene signature (CDK1, CCNB1, CCNB2, BUB1 and KIF11) as a significant independent prognostic factor.

Identification of Hub Genes Associated With Immune Infiltration and Predict Prognosis in Hepatocellular Carcinoma via Bioinformatics Approaches

Aims

In the cancer-related research field, there is currently a major need for a greater number of valuable biomarkers to predict the prognosis of hepatocellular carcinoma (HCC). In this study, we aimed to screen hub genes related to immune cell infiltration and explore their prognostic value for HCC.

Methods

We analyzed five datasets (GSE46408, GSE57957, GSE74656, GSE76427, and GSE87630) from the Gene Expression Omnibus database to screen the differentially expressed genes (DEGs). A protein-protein interaction network of the DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes; then, the hub genes were identified. Functional enrichment of the genes was performed on the Metascape website. Next, the expression of these hub genes was validated in several databases, including Oncomine, Gene Expression Profiling Interactive Analysis 2 (GEPIA2), and Human Protein Atlas. We explored the correlations between the hub genes and infiltrated immune cells in the TIMER2.0 database. The survival curves were generated in GEPIA2, and the univariate and multivariate Cox regression analyses were performed using TIMER2.0.

Results

The top ten hub genes [DNA topoisomerase II alpha (TOP2A), cyclin B2 (CCNB2), protein regulator of cytokinesis 1 (PRC1), Rac GTPase-activating protein 1 (RACGAP1), aurora kinase A (AURKA), cyclin-dependent kinase inhibitor 3 (CDKN3), nucleolar and spindle-associated protein 1 (NUSAP1), cell division cycle-associated 5 (CDCA5), abnormal spindle microtubule assembly (ASPM), and non-SMC condensin I complex subunit G (NCAPG)] were identified in subsequent analysis. These genes are most markedly enriched in cell division, suggesting their close association with tumorigenesis. Multi-database analyses validated that the hub genes were upregulated in HCC tissues. All hub genes positively correlated with several types of immune infiltration, including B cells, CD4⁺ T cells, macrophages, and dendritic cells. Furthermore, these hub genes served as independent prognostic factors, and the expression of these hub genes combing with the macrophage levels could help predict an unfavorable prognosis of HCC.

Conclusion

In sum, these hub genes (TOP2A, CCNB2, PRC1, RACGAP1, AURKA, CDKN3, NUSAP1, CDCA5, ASPM, and NCAPG) may be pivotal markers for prognostic prediction as well as potentially work as targets for immune-based intervention strategies in HCC.

c-Src promotes the growth and tumorigenesis of hepatocellular carcinoma via the Hippo signaling pathway

We investigated the association between c-Src and the progression of hepatocellular carcinoma (HCC) and its underlying mechanisms. The relationship between c-Src expression and the occurrence and development of HCC was explored using GEPIA and further confirmed by western blotting analysis and real-time quantitative PCR. CCK-8, flow cytometry, Transwell, and wound-healing assays were conducted to analyze the effects of c-Src on the growth, cell cycle, apoptosis, migration, and infiltration of HCC cells. Mouse models of transplanted xenogeneic human tumors were constructed to explore the effects of c-Src on HCC tumor growth. Compared with that in adjacent normal liver tissues, the expression level of c-Src in HCC tissues was significantly increased and was negatively correlated with patient survival. These findings are consistent with those in the GEPIA database. Downregulation of c-Src expression can inhibit the growth, infiltration, and migration of HCC cells. c-Src impeded the translocation of YAP from the nucleus to the cytoplasm and promoted Yes-associated protein transcriptional activity. In vivo experiments showed that c-Src inhibition suppressed tumor growth in mice. We found that c-Src can promote the growth and tumorigenesis of HCC cells by activating the Hippo signaling pathway.

v-myb avian myeloblastosis viral oncogene homolog expression is a potential molecular diagnostic marker for B-cell acute lymphoblastic leukemia

BACKGROUND

B-cell acute lymphoblastic leukemia (B-ALL) is the most commonly diagnosed childhood malignancy worldwide and is especially common in Mexico. Additionally, the number of cases has increased in recent years. Thus, it is very important to develop molecular strategies to diagnose leukemia. The aim of this study was to investigate MYB expression and to determine its impact on the diagnosis of B-ALL.

METHODS

We analyzed the B-ALL gene expression profile by microarray data mining. Bioinformatics analysis was performed to identify the genes that are overexpressed in leukemia. We determined that MYB was highly expressed in leukemia. Then, we validated MYB expression in 70 patients with B-ALL and in 16 healthy controls (HCs) using qRT-PCR. The results were statistically analyzed using the Kolmogorov-Smirnov Z test, Mann-Whitney U test, receiver operating characteristic curves, and the Youden index.

RESULTS

The microarrays showed that MYB was overexpressed in B-ALL patients with a fold change of 57.8728 and a P value of 2.56^-195 . MYB expression showed great variability among the patients analyzed. However, compared to the HCs, the B-ALL patients had a P value < .0001, an area under the curve of 0.813, and a Youden index of 1.46, indicating the statistical significance.

CONCLUSION

MYB expression in B-ALL cells could be a potential molecular marker for childhood leukemia.

MiR-30b-5p inhibits proliferation and promotes apoptosis of medulloblastoma cells via targeting MYB proto-oncogene like 2 (MYBL2)

Medulloblastoma (MB) is the most common malignant brain tumors among children. MiR-30b-5p is a potential tumor suppressor in a variety of human cancers. However, its expression and function in MB remain poorly understood. This study aimed to investigate the expression, role and regulatory mechanism of miR-30b-5p in MB. The expression of miR-30b-5p in MB tissues and cell lines was detected by real-time PCR. The effects of miR-30b-5p on cell proliferation and apoptosis were monitored by CCK-8 (Cell Counting Kit-8) assay, colony formation assay and flow cytometry, respectively. Bioinformatics database TargetScan predicted the target genes of miR-30b-5p. The interaction between miR-30b-5p and MYB proto-oncogene Like 2 (MYBL2) was determined by luciferase reporter gene assay. We demonstrated that the expression of miR-30b-5p was significantly downregulated in MB. Upregulated miR-30b-5p could inhibit the proliferation and induce apoptosis of MB.

Moreover, overexpressed miR-30b-5p could increase the expression of BAX but decrease that of Bcl-2. Downregulated miR-30b-5p exerted the opposite effect. MYBL2 was proved to be the target gene of miR-30b-5p and was negatively regulated by miR-30b-5p. These results indicate that miR-30b-5p inhibits the progression of MB via targeting the expression of MYBL2.

COX5B-Mediated Bioenergetic Alteration Regulates Tumor Growth and Migration by Modulating AMPK-UHMK1-ERK Cascade in Hepatoma

The oxidative phosphorylation machinery in mitochondria, which generates the main bioenergy pool in cells, includes four enzyme complexes for electron transport and ATP synthase. Among them, the cytochrome c oxidase (COX), which constitutes the fourth complex, has been suggested as the major regulatory site. Recently, abnormalities in COX were linked to tumor progression in several cancers. However, it remains unclear whether COX and its subunits play a role in tumor progression of hepatoma. To search for the key regulatory factor(s) in COX for hepatoma development, in silico analysis using public transcriptomic database followed by validation for postoperative outcome associations using independent in-house patient cohorts was performed. In which, COX5B was highly expressed in hepatoma and associated with unfavorable postoperative prognosis. In addressing the role of COX5B in hepatoma, the loss- and gain-of-function experiments for COX5B were conducted. Consequently, COX5B expression was associated with increased hepatoma cell proliferation, migration and xenograft growth. Downstream effectors searched by cDNA microarray analysis identified UHMK1, an oncogenic protein, which manifested a positively correlated expression level of COX5B. The COX5B-mediated regulatory event on UHMK1 expression was subsequently demonstrated as bioenergetic alteration-dependent activation of AMPK in hepatoma cells. Phosphoproteomic analysis uncovered activation of ERK- and stathmin-mediated pathways downstream of UHMK1. Finally, comprehensive phenotypic assays supported the impacts of COX5B-UHMK1-ERK axis on hepatoma cell growth and migration.

Regulation of Hippo signaling and triple negative breast cancer progression by an ubiquitin ligase RNF187

Breast cancer is the most common malignancy for women worldwide, while Triple Negative Breast Cancer (TNBC) accounts for 20% in all patients. Compared with estrogen receptor positive breast cancer, which could be effectively controlled via endocrine therapy, TNBC is more aggressive and worse in prognosis. It is therefore urgent and necessary to develop a novel therapeutic strategy for TNBC treatment. Recent studies identified Hippo signaling is highly activated in TNBC, which could be a driving pathway for TNBC progression. In our study, we determine RNF187 as a negative regulator for Hippo signaling activation. RNF187 depletion significantly decreases cell migration and invasion capacity in TNBC. These effects could be rescued by further YAP depletion. Depletion of RNF187 increases the YAP protein level and Hippo signaling target genes, such as CTGF and CYR61 in TNBC. Immuno-precipitation assay shows that RNF187 associates with YAP, promoting its degradation possibly via inducing YAP K48-dependent poly-ubiquitination. Interestingly, Our clinical data reveals that RNF187 reversely correlates with YAP protein level and Hippo target genes. RNF187 tends to correlate with good prognosis in TNBC patients. Our study provides evidence to establish a proteolytic mechanism in regulation Hippo signaling activation in TNBC.

Screening and identification of genes associated with cell proliferation in cholangiocarcinoma

Cholangiocarcinoma (CCA), an aggressive tumor with poor prognosis, is a malignant cancer with increasing incidence and mortality rates. It is important to survey crucial genes in CCA to find and design potential drug targets, especially for those genes associated with cell proliferation that is a key biological process in tumorgenesis. Herein, we surveyed genes associated with cell proliferation via a comprehensive pan-cancer analysis. Candidate genes were further analyzed using multiple approaches, including cross-analysis from diverse molecular levels, examination of potential function and interactions, and additional experimental validation. We primarily screened 15 potential genes based on 11 validated genes, and these 26 genes were further examined to delineate their biological functions and potential roles in cancer treatment. Several of them were involved synthetically lethal genetic interactions, especially for RECQL4, TOP2A, MKI67 and ASPM, indicating their potential roles in drug design and cancer treatment. Further experimental validation indicated that some genes were significantly upregulated in several cancer cell lines, implying their important roles in tumorigenesis. Our study identifies some genes associated with cell proliferation, which may be potential future targets in molecular targeted therapy.

Common and distinct features of potentially predictive biomarkers in small cell lung carcinoma and large cell neuroendocrine carcinoma of the lung by systematic and integrated analysis

BACKGROUND

Large-cell neuroendocrine carcinoma of the lung (LCNEC) and small-cell lung carcinoma (SCLC) are neuroendocrine neoplasms. However, the underlying mechanisms of common and distinct genetic characteristics between LCNEC and SCLC are currently unclear. Herein, protein expression profiles and possible interactions with miRNAs were provided by integrated bioinformatics analysis, in order to explore core genes associated with tumorigenesis and prognosis in SCLC and LCNEC.

METHODS

GSE1037 gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) in LCNEC and SCLC, as compared with normal lung tissues, were selected using the GEO2R online analyzer and Venn diagram software. Gene ontology (GO) analysis was performed using Database for Annotation, Visualization and Integrated Discovery. The biological pathway analysis was performed using the FunRich database. Subsequently, a protein-protein interaction (PPI) network of DEGs was generated using Search Tool for the Retrieval of Interacting Genes and displayed via Cytoscape software. The PPI network was analyzed by the Molecular Complex Detection app from Cytoscape, and 16 upregulated hub genes were selected. The Oncomine database was used to detect expression patterns of hub genes for validation. Furthermore, the biological pathways of these 16 hub genes were re-analyzed, and potential interactions between these genes and miRNAs were explored via FunRich.

RESULTS

A total of 384 DEGs were identified. A Venn diagram determined 88 common DEGs. The PPI network was constructed with 48 nodes and 221 protein pairs. Among them, 16 hub genes were extracted, 14 of which were upregulated in SCLC samples, as compared with normal lung specimens, and 10 were correlated with the cell cycle pathway. Furthermore, 57 target miRNAs for 8 hub genes were identified, among which 31 miRNAs were correlated with the progression of carcinoma, drug-resistance, radio-sensitivity, or autophagy in lung cancer.

CONCLUSION

This study provided effective biomarkers and novel therapeutic targets for diagnosis and prognosis of SCLC and LCNEC.

TAZ target gene ITGAV regulates invasion and feeds back positively on YAP and TAZ in liver cancer cells

The Hippo pathway effectors yes-associated protein (YAP) and WW domain containing transcription regulator 1 (TAZ/WWTR1) support tumor initiation and progression in various cancer entities including hepatocellular carcinoma (HCC). However, to which extent YAP and TAZ contribute to liver tumorigenesis via common and exclusive molecular mechanisms is poorly understood. RNAinterference (RNAi) experiments illustrate that YAP and TAZ individually support HCC cell viability and migration, while for invasion additive effects were observed. Comprehensive expression profiling revealed partly overlapping YAP/TAZ target genes as well as exclusively regulated genes. Integrin-αV (ITGAV) is a novel TAZ-specific target gene, whose overexpression in human HCC patients correlates with poor clinical outcome, TAZ expression in HCCs, and the abundance of YAP/TAZ target genes. Functionally, ITGAV contributes to actin stress fiber assembly, tumor cell migration and invasion. Perturbation of ITGAV diminishes actin fiber formation and nuclear YAP/TAZ protein levels. We describe a novel Hippo downstream mechanism in HCC cells, which is regulated by TAZ and ITGAV and that feedbacks on YAP/TAZ activity. This mechanism may represent a therapeutic target structure since it contributes to signal amplification of oncogenic YAP/TAZ in hepatocarcinogenesis.